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Interrupt-driven programs are widely used in aerospace, medical equipment, and other embedded systems that require extreme safety and stability. However, uncertain interrupt interleaving executions may cause serious data race problems. Static analysis is an important technology to detect data race problems. Existing methods are either too conservative to have low accuracy, or bring lots of false alarms, there still need a more effective solution. The program verification tool CBMC has an excellent performance in the analysis and verification of C multi-threaded modeling, but it doesn't support interrupt-driven programs. In this paper, we proposed a method based on CBMC to detect data race in interrupt-driven programs. Our method achieved accurate analysis of interrupt-driven programs by performing analysis toward interrupt preemption and synchronization semantics, and further validation of the program can be supported. Experiments results on related benchmarks demonstrate our approach's usability and effectiveness.

In this letter, a Tomlinson-Harashima precoding (THP) scheme is proposed for the downlink of multiuser MIMO systems with multiple antennas at each receiver. Assuming single data stream communication for each user, joint transmitter and receiver design is done to maximize the signal to noise ratio (SNR) for each user. Furthermore, a heuristic user ordering algorithm is proposed to optimize the encoding order and improve the bit error rate (BER) performance. Simulation results have shown that the proposed approach is superior to some existing precoding schemes.

A novel low-complexity iterative receiver for coded multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems is proposed in this letter. The iterative receiver uses the parallel interference cancellation (PIC)-maximum ratio combining (MRC) detector for MIMO-OFDM detection, which is a popular alternative to the minimum mean square error (MMSE) detector due to its lower computational complexity. However, we have found that the conventional PIC-MRC detector tends to underestimate the magnitude of its output log likelihood ratios (LLRs). Based on this discovery, we propose to multiply these LLRs by a constant factor, which is optimized according to the extrinsic information transfer (EXIT) chart of the soft-in soft-out (SISO) detector. Simulation results show that the proposed scheme significantly improves the performance of the PIC-MRC-based receiver with little additional cost in computational complexity, allowing it to closely approach the performance of receiver using the much more complex MMSE detector.

Software framework is a very important approach to realize software reuse and improve the software quality. In this paper, we firstly introduce a new software framework named QFusion to complete cross-platform desktop software development, which is based on function plug-in module. The QFusion framework can realize information interaction by use of event bus, data bus and service, which can separate the graphical user interfaces (GUI) from data processing completely. Based on the framework-related develop process, the complexity is largely reduced. Secondly, we give the practice of QFusion framework in modern military field to implement the feature extraction and data processing algorithm. Benefit from the QFusion framework, the signal processing task is completed by the collaboration among three groups, including data generation plug-in development group, data processing plug-in development group and GUI plug-in development group, respectively. Finally, the signal processing results are presented to prove the validity of the QFusion framework, which lays a solid foundation for solving the practical problem in engineering application.

In this paper, we propose a reduced complexity iterative receiver for coded multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems. We apply the matched filter (MF) in the proposed scheme, which is a popular alternative to the minimum mean square error (MMSE) detector due to its lower computational complexity. We improve the well studied MF-based iterative MIMO soft-detector by scaling the value of the a priori information from a soft-in soft-out (SISO) channel decoder. The scaling factor is optimized according to the extrinsic information transfer (EXIT) chart of the SISO detector. Simulation results show that the proposed MF- based iterative receiver significantly outperforms the conventional one with little additional cost in computational complexity and achieves bit error rate (BER) performance comparable to that of the MMSE-based iterative receiver with much lower complexity.

The paper consider a scheme combining transmit antenna selection (TAS) and space time turbo trellis codes (ST-turbo-TCs), which is referred to as the ST-turbo-TCs/TAS scheme. We choose two transmit antennas, which maximizes the signal-to-noise ratio (SNR) at the receiver, to transmit the baseline ST-Turbo-TCs signals designed for two transmit antennas. Our simulation shows that this scheme can achieve significant performance gains with an increasing number of transmit antenna available for selection. In addition, this scheme does not have increasing complexity for increasing performance gains, and does not need a particular code design for a large number of transmit antennas.